Initial implementation of 'change-key-password' command of SOP-07

external-sop/src/main/java/sop/external/operation/ChangeKeyPasswordExternal.java

@@ -0,0 +1,57 @@
+// SPDX-FileCopyrightText: 2023 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package sop.external.operation;
+
+import sop.Ready;
+import sop.exception.SOPGPException;
+import sop.external.ExternalSOP;
+import sop.operation.ChangeKeyPassword;
+
+import java.io.InputStream;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Properties;
+
+public class ChangeKeyPasswordExternal implements ChangeKeyPassword {
+    private final List<String> commandList = new ArrayList<>();
+    private final List<String> envList;
+
+    private int keyPasswordCounter = 0;
+
+    public ChangeKeyPasswordExternal(String binary, Properties environment) {
+        this.commandList.add(binary);
+        this.commandList.add("decrypt");
+        this.envList = ExternalSOP.propertiesToEnv(environment);
+    }
+
+    @Override
+    public ChangeKeyPassword noArmor() {
+        this.commandList.add("--no-armor");
+        return this;
+    }
+
+    @Override
+    public ChangeKeyPassword oldKeyPassphrase(String oldPassphrase) {
+        this.commandList.add("--old-key-password=@ENV:KEY_PASSWORD_" + keyPasswordCounter);
+        this.envList.add("KEY_PASSWORD_" + keyPasswordCounter + "=" + oldPassphrase);
+        keyPasswordCounter++;
+
+        return this;
+    }
+
+    @Override
+    public ChangeKeyPassword newKeyPassphrase(String newPassphrase) {
+        this.commandList.add("--new-key-password=@ENV:KEY_PASSWORD_" + keyPasswordCounter);
+        this.envList.add("KEY_PASSWORD_" + keyPasswordCounter + "=" + newPassphrase);
+        keyPasswordCounter++;
+
+        return this;
+    }
+
+    @Override
+    public Ready keys(InputStream inputStream) throws SOPGPException.KeyIsProtected, SOPGPException.BadData {
+        return ExternalSOP.executeTransformingOperation(Runtime.getRuntime(), commandList, envList, inputStream);
+    }
+}